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What are work vessels?

Work vessels are generally vessels that move at a slow pace and are likely to be stationary for periods of time.

They include:

  • tugs
  • barges
  • dredges
  • defence vessels
  • military ships
  • heavy lift vessels.

What you must do

The Craft Risk Management Standard (CRMS) for Biofouling outlines the requirements for vessels coming to New Zealand.

Guidance on how to meet CRMS requirements is available in our:

Long-stay work vessels

Most work vessels arriving in New Zealand fall under the CRMS long-stay category. Long-stay vessels are those planning to be in New Zealand for 21 days or more, or visiting ports that aren't places of first arrival.

Long-stay vessels should meet the CRMS requirements by providing evidence that the entire hull, including niche areas, has been cleaned less than 30 days before arrival in New Zealand.

Short-stay work vessels

Work vessels coming to New Zealand for fewer than 21 days and only visiting approved ports can meet the requirements by providing evidence of continual maintenance using best practices.

Providing evidence of cleaning

For long-stay vessels, arrange a biofouling inspection by an appropriately qualified provider and provide the evidence to MPI before leaving for New Zealand. Evidence may include documentation from cleaning or treatment of the hull and niche areas, such as dry docking or in-water cleaning reports. This is especially important for vessels coming to New Zealand for extended periods, such as those being brought here permanently.

Cleaning means the removal of all biofouling (other than a slime layer and gooseneck barnacles) from all hull and niche areas.

Cleaning with an MPI-approved treatment supplier

If you plan to have your vessel hauled out or re-fitted in New Zealand, you may comply with the CRMS by:

  • booking an appointment for haul out with an MPI-approved treatment supplier (the booking time must be within 24 hours of arrival).
  • giving MPI evidence of your booking with the provider.

Find MPI-approved NZ treatment suppliers 

Continual maintenance of short-stay vessels

Continual maintenance involves ongoing management of biofouling, including:

  • developing and maintaining a Biofouling Management Plan specific to the vessel
  • keeping records of biofouling management in a biofouling record book
  • coating the hull and niche areas with antifouling paint appropriate to the operating profile of the vessel
  • regularly inspecting and cleaning the hull and niche areas
  • having contingency plans in place to minimise fouling if the vessel falls out of its operational  profile.

Most work vessels require cleaning following periods of being stationary in addition to continual maintenance.

Providing evidence of continual maintenance

Before short-stay work vessels arrive, MPI will ask to see evidence of the above measures. Evidence must be verifiable and may include:

  • your Biofouling Management Plan and record book
  • dates and reports of dry docking
  • current antifouling system certificates
  • vessel operational history
  • evidence of independent inspections and ongoing maintenance (such as cleaning or treatment) by suitably qualified people.

Use suitable hull antifouling

The vessel hull should be painted with antifouling that can prevent biofouling between dry dockings.  The paint applied should take into account:

  • the planned time between dry dockings
  • the ship's speed and activity
  • any periods that the vessel will be stationary.

Where antifouling paint is damaged, consider in-water repair of the paint in the area, even if minor. 

Maintain, inspect and clean niche areas

Niche areas are protrusions, recesses, or unpainted areas of the hull, which are particularly susceptible to biofouling. It is important to show evidence that all niche areas have been managed for biofouling.

Work Vessel with close ups of niche areas

Sea chests

  • Paint internal surfaces with antifouling paints suitable for the flow of seawater.
  • Use marine growth prevention systems (MGPSs), such as chemical dosing systems, where possible.
  • Regularly use steam blow-out pipes if fitted in sea chests to reduce biofouling growth.

Sea inlet pipes and outlets

Apply antifouling paint inside pipe openings and pipework. Antifouling paint adheres and lasts longer if:

  • all sea inlet pipes and outlets are rounded
  • grates on seawater intakes are made with round bars.

Hull appendages as niches

Any hull appendages can act as niche areas, even when painted with effective antifouling. You may need to include them in a maintenance programme. Hull appendages include:

  • dry docking support strips
  • bow and stern thrusters
  • bilge keels, cooling scoops and propulsion scoops
  • rudder hinges and stabiliser fin apertures.

Hull appendages that can't be painted with antifouling paint – because it affects their operation – may need additional maintenance and cleaning. These include:

  • anodes
  • velocity probes
  • echo sounders.

Internal seawater systems

Effective marine growth protection systems (MGPSs) can be fitted to internal seawater systems prone to biofouling. Use these systems regularly and monitor them to make sure they're working well. If MGPSs haven't been fitted or haven't prevented biofouling, treat internal systems before arriving in New Zealand.

Find out more

Who to contact

If you have questions about biofouling requirements for work vessels, email standards@mpi.govt.nz 

MPI business units